1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2010 Red Hat Inc.
4  * Author : Dave Airlie <airlied@redhat.com>
5  *
6  * ATPX support for both Intel/ATI
7  */
8 #include <linux/vga_switcheroo.h>
9 #include <linux/slab.h>
10 #include <linux/acpi.h>
11 #include <linux/pci.h>
12 #include <linux/delay.h>
13 
14 #include "radeon_acpi.h"
15 
16 struct radeon_atpx_functions {
17 	bool px_params;
18 	bool power_cntl;
19 	bool disp_mux_cntl;
20 	bool i2c_mux_cntl;
21 	bool switch_start;
22 	bool switch_end;
23 	bool disp_connectors_mapping;
24 	bool disp_detetion_ports;
25 };
26 
27 struct radeon_atpx {
28 	acpi_handle handle;
29 	struct radeon_atpx_functions functions;
30 	bool is_hybrid;
31 	bool dgpu_req_power_for_displays;
32 };
33 
34 static struct radeon_atpx_priv {
35 	bool atpx_detected;
36 	bool bridge_pm_usable;
37 	/* handle for device - and atpx */
38 	acpi_handle dhandle;
39 	struct radeon_atpx atpx;
40 } radeon_atpx_priv;
41 
42 struct atpx_verify_interface {
43 	u16 size;		/* structure size in bytes (includes size field) */
44 	u16 version;		/* version */
45 	u32 function_bits;	/* supported functions bit vector */
46 } __packed;
47 
48 struct atpx_px_params {
49 	u16 size;		/* structure size in bytes (includes size field) */
50 	u32 valid_flags;	/* which flags are valid */
51 	u32 flags;		/* flags */
52 } __packed;
53 
54 struct atpx_power_control {
55 	u16 size;
56 	u8 dgpu_state;
57 } __packed;
58 
59 struct atpx_mux {
60 	u16 size;
61 	u16 mux;
62 } __packed;
63 
64 bool radeon_has_atpx(void) {
65 	return radeon_atpx_priv.atpx_detected;
66 }
67 
68 bool radeon_has_atpx_dgpu_power_cntl(void) {
69 	return radeon_atpx_priv.atpx.functions.power_cntl;
70 }
71 
72 bool radeon_is_atpx_hybrid(void) {
73 	return radeon_atpx_priv.atpx.is_hybrid;
74 }
75 
76 bool radeon_atpx_dgpu_req_power_for_displays(void) {
77 	return radeon_atpx_priv.atpx.dgpu_req_power_for_displays;
78 }
79 
80 /**
81  * radeon_atpx_call - call an ATPX method
82  *
83  * @handle: acpi handle
84  * @function: the ATPX function to execute
85  * @params: ATPX function params
86  *
87  * Executes the requested ATPX function (all asics).
88  * Returns a pointer to the acpi output buffer.
89  */
90 static union acpi_object *radeon_atpx_call(acpi_handle handle, int function,
91 					   struct acpi_buffer *params)
92 {
93 	acpi_status status;
94 	union acpi_object atpx_arg_elements[2];
95 	struct acpi_object_list atpx_arg;
96 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
97 
98 	atpx_arg.count = 2;
99 	atpx_arg.pointer = &atpx_arg_elements[0];
100 
101 	atpx_arg_elements[0].type = ACPI_TYPE_INTEGER;
102 	atpx_arg_elements[0].integer.value = function;
103 
104 	if (params) {
105 		atpx_arg_elements[1].type = ACPI_TYPE_BUFFER;
106 		atpx_arg_elements[1].buffer.length = params->length;
107 		atpx_arg_elements[1].buffer.pointer = params->pointer;
108 	} else {
109 		/* We need a second fake parameter */
110 		atpx_arg_elements[1].type = ACPI_TYPE_INTEGER;
111 		atpx_arg_elements[1].integer.value = 0;
112 	}
113 
114 	status = acpi_evaluate_object(handle, NULL, &atpx_arg, &buffer);
115 
116 	/* Fail only if calling the method fails and ATPX is supported */
117 	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
118 		printk("failed to evaluate ATPX got %s\n",
119 		       acpi_format_exception(status));
120 		kfree(buffer.pointer);
121 		return NULL;
122 	}
123 
124 	return buffer.pointer;
125 }
126 
127 /**
128  * radeon_atpx_parse_functions - parse supported functions
129  *
130  * @f: supported functions struct
131  * @mask: supported functions mask from ATPX
132  *
133  * Use the supported functions mask from ATPX function
134  * ATPX_FUNCTION_VERIFY_INTERFACE to determine what functions
135  * are supported (all asics).
136  */
137 static void radeon_atpx_parse_functions(struct radeon_atpx_functions *f, u32 mask)
138 {
139 	f->px_params = mask & ATPX_GET_PX_PARAMETERS_SUPPORTED;
140 	f->power_cntl = mask & ATPX_POWER_CONTROL_SUPPORTED;
141 	f->disp_mux_cntl = mask & ATPX_DISPLAY_MUX_CONTROL_SUPPORTED;
142 	f->i2c_mux_cntl = mask & ATPX_I2C_MUX_CONTROL_SUPPORTED;
143 	f->switch_start = mask & ATPX_GRAPHICS_DEVICE_SWITCH_START_NOTIFICATION_SUPPORTED;
144 	f->switch_end = mask & ATPX_GRAPHICS_DEVICE_SWITCH_END_NOTIFICATION_SUPPORTED;
145 	f->disp_connectors_mapping = mask & ATPX_GET_DISPLAY_CONNECTORS_MAPPING_SUPPORTED;
146 	f->disp_detetion_ports = mask & ATPX_GET_DISPLAY_DETECTION_PORTS_SUPPORTED;
147 }
148 
149 /**
150  * radeon_atpx_validate() - validate ATPX functions
151  *
152  * @atpx: radeon atpx struct
153  *
154  * Validate that required functions are enabled (all asics).
155  * returns 0 on success, error on failure.
156  */
157 static int radeon_atpx_validate(struct radeon_atpx *atpx)
158 {
159 	u32 valid_bits = 0;
160 
161 	if (atpx->functions.px_params) {
162 		union acpi_object *info;
163 		struct atpx_px_params output;
164 		size_t size;
165 
166 		info = radeon_atpx_call(atpx->handle, ATPX_FUNCTION_GET_PX_PARAMETERS, NULL);
167 		if (!info)
168 			return -EIO;
169 
170 		memset(&output, 0, sizeof(output));
171 
172 		size = *(u16 *) info->buffer.pointer;
173 		if (size < 10) {
174 			printk("ATPX buffer is too small: %zu\n", size);
175 			kfree(info);
176 			return -EINVAL;
177 		}
178 		size = min(sizeof(output), size);
179 
180 		memcpy(&output, info->buffer.pointer, size);
181 
182 		valid_bits = output.flags & output.valid_flags;
183 
184 		kfree(info);
185 	}
186 
187 	/* if separate mux flag is set, mux controls are required */
188 	if (valid_bits & ATPX_SEPARATE_MUX_FOR_I2C) {
189 		atpx->functions.i2c_mux_cntl = true;
190 		atpx->functions.disp_mux_cntl = true;
191 	}
192 	/* if any outputs are muxed, mux controls are required */
193 	if (valid_bits & (ATPX_CRT1_RGB_SIGNAL_MUXED |
194 			  ATPX_TV_SIGNAL_MUXED |
195 			  ATPX_DFP_SIGNAL_MUXED))
196 		atpx->functions.disp_mux_cntl = true;
197 
198 	/* some bioses set these bits rather than flagging power_cntl as supported */
199 	if (valid_bits & (ATPX_DYNAMIC_PX_SUPPORTED |
200 			  ATPX_DYNAMIC_DGPU_POWER_OFF_SUPPORTED))
201 		atpx->functions.power_cntl = true;
202 
203 	atpx->is_hybrid = false;
204 	if (valid_bits & ATPX_MS_HYBRID_GFX_SUPPORTED) {
205 		printk("ATPX Hybrid Graphics\n");
206 		/*
207 		 * Disable legacy PM methods only when pcie port PM is usable,
208 		 * otherwise the device might fail to power off or power on.
209 		 */
210 		atpx->functions.power_cntl = !radeon_atpx_priv.bridge_pm_usable;
211 		atpx->is_hybrid = true;
212 	}
213 
214 	return 0;
215 }
216 
217 /**
218  * radeon_atpx_verify_interface - verify ATPX
219  *
220  * @atpx: radeon atpx struct
221  *
222  * Execute the ATPX_FUNCTION_VERIFY_INTERFACE ATPX function
223  * to initialize ATPX and determine what features are supported
224  * (all asics).
225  * returns 0 on success, error on failure.
226  */
227 static int radeon_atpx_verify_interface(struct radeon_atpx *atpx)
228 {
229 	union acpi_object *info;
230 	struct atpx_verify_interface output;
231 	size_t size;
232 	int err = 0;
233 
234 	info = radeon_atpx_call(atpx->handle, ATPX_FUNCTION_VERIFY_INTERFACE, NULL);
235 	if (!info)
236 		return -EIO;
237 
238 	memset(&output, 0, sizeof(output));
239 
240 	size = *(u16 *) info->buffer.pointer;
241 	if (size < 8) {
242 		printk("ATPX buffer is too small: %zu\n", size);
243 		err = -EINVAL;
244 		goto out;
245 	}
246 	size = min(sizeof(output), size);
247 
248 	memcpy(&output, info->buffer.pointer, size);
249 
250 	/* TODO: check version? */
251 	printk("ATPX version %u, functions 0x%08x\n",
252 	       output.version, output.function_bits);
253 
254 	radeon_atpx_parse_functions(&atpx->functions, output.function_bits);
255 
256 out:
257 	kfree(info);
258 	return err;
259 }
260 
261 /**
262  * radeon_atpx_set_discrete_state - power up/down discrete GPU
263  *
264  * @atpx: atpx info struct
265  * @state: discrete GPU state (0 = power down, 1 = power up)
266  *
267  * Execute the ATPX_FUNCTION_POWER_CONTROL ATPX function to
268  * power down/up the discrete GPU (all asics).
269  * Returns 0 on success, error on failure.
270  */
271 static int radeon_atpx_set_discrete_state(struct radeon_atpx *atpx, u8 state)
272 {
273 	struct acpi_buffer params;
274 	union acpi_object *info;
275 	struct atpx_power_control input;
276 
277 	if (atpx->functions.power_cntl) {
278 		input.size = 3;
279 		input.dgpu_state = state;
280 		params.length = input.size;
281 		params.pointer = &input;
282 		info = radeon_atpx_call(atpx->handle,
283 					ATPX_FUNCTION_POWER_CONTROL,
284 					&params);
285 		if (!info)
286 			return -EIO;
287 		kfree(info);
288 
289 		/* 200ms delay is required after off */
290 		if (state == 0)
291 			msleep(200);
292 	}
293 	return 0;
294 }
295 
296 /**
297  * radeon_atpx_switch_disp_mux - switch display mux
298  *
299  * @atpx: atpx info struct
300  * @mux_id: mux state (0 = integrated GPU, 1 = discrete GPU)
301  *
302  * Execute the ATPX_FUNCTION_DISPLAY_MUX_CONTROL ATPX function to
303  * switch the display mux between the discrete GPU and integrated GPU
304  * (all asics).
305  * Returns 0 on success, error on failure.
306  */
307 static int radeon_atpx_switch_disp_mux(struct radeon_atpx *atpx, u16 mux_id)
308 {
309 	struct acpi_buffer params;
310 	union acpi_object *info;
311 	struct atpx_mux input;
312 
313 	if (atpx->functions.disp_mux_cntl) {
314 		input.size = 4;
315 		input.mux = mux_id;
316 		params.length = input.size;
317 		params.pointer = &input;
318 		info = radeon_atpx_call(atpx->handle,
319 					ATPX_FUNCTION_DISPLAY_MUX_CONTROL,
320 					&params);
321 		if (!info)
322 			return -EIO;
323 		kfree(info);
324 	}
325 	return 0;
326 }
327 
328 /**
329  * radeon_atpx_switch_i2c_mux - switch i2c/hpd mux
330  *
331  * @atpx: atpx info struct
332  * @mux_id: mux state (0 = integrated GPU, 1 = discrete GPU)
333  *
334  * Execute the ATPX_FUNCTION_I2C_MUX_CONTROL ATPX function to
335  * switch the i2c/hpd mux between the discrete GPU and integrated GPU
336  * (all asics).
337  * Returns 0 on success, error on failure.
338  */
339 static int radeon_atpx_switch_i2c_mux(struct radeon_atpx *atpx, u16 mux_id)
340 {
341 	struct acpi_buffer params;
342 	union acpi_object *info;
343 	struct atpx_mux input;
344 
345 	if (atpx->functions.i2c_mux_cntl) {
346 		input.size = 4;
347 		input.mux = mux_id;
348 		params.length = input.size;
349 		params.pointer = &input;
350 		info = radeon_atpx_call(atpx->handle,
351 					ATPX_FUNCTION_I2C_MUX_CONTROL,
352 					&params);
353 		if (!info)
354 			return -EIO;
355 		kfree(info);
356 	}
357 	return 0;
358 }
359 
360 /**
361  * radeon_atpx_switch_start - notify the sbios of a GPU switch
362  *
363  * @atpx: atpx info struct
364  * @mux_id: mux state (0 = integrated GPU, 1 = discrete GPU)
365  *
366  * Execute the ATPX_FUNCTION_GRAPHICS_DEVICE_SWITCH_START_NOTIFICATION ATPX
367  * function to notify the sbios that a switch between the discrete GPU and
368  * integrated GPU has begun (all asics).
369  * Returns 0 on success, error on failure.
370  */
371 static int radeon_atpx_switch_start(struct radeon_atpx *atpx, u16 mux_id)
372 {
373 	struct acpi_buffer params;
374 	union acpi_object *info;
375 	struct atpx_mux input;
376 
377 	if (atpx->functions.switch_start) {
378 		input.size = 4;
379 		input.mux = mux_id;
380 		params.length = input.size;
381 		params.pointer = &input;
382 		info = radeon_atpx_call(atpx->handle,
383 					ATPX_FUNCTION_GRAPHICS_DEVICE_SWITCH_START_NOTIFICATION,
384 					&params);
385 		if (!info)
386 			return -EIO;
387 		kfree(info);
388 	}
389 	return 0;
390 }
391 
392 /**
393  * radeon_atpx_switch_end - notify the sbios of a GPU switch
394  *
395  * @atpx: atpx info struct
396  * @mux_id: mux state (0 = integrated GPU, 1 = discrete GPU)
397  *
398  * Execute the ATPX_FUNCTION_GRAPHICS_DEVICE_SWITCH_END_NOTIFICATION ATPX
399  * function to notify the sbios that a switch between the discrete GPU and
400  * integrated GPU has ended (all asics).
401  * Returns 0 on success, error on failure.
402  */
403 static int radeon_atpx_switch_end(struct radeon_atpx *atpx, u16 mux_id)
404 {
405 	struct acpi_buffer params;
406 	union acpi_object *info;
407 	struct atpx_mux input;
408 
409 	if (atpx->functions.switch_end) {
410 		input.size = 4;
411 		input.mux = mux_id;
412 		params.length = input.size;
413 		params.pointer = &input;
414 		info = radeon_atpx_call(atpx->handle,
415 					ATPX_FUNCTION_GRAPHICS_DEVICE_SWITCH_END_NOTIFICATION,
416 					&params);
417 		if (!info)
418 			return -EIO;
419 		kfree(info);
420 	}
421 	return 0;
422 }
423 
424 /**
425  * radeon_atpx_switchto - switch to the requested GPU
426  *
427  * @id: GPU to switch to
428  *
429  * Execute the necessary ATPX functions to switch between the discrete GPU and
430  * integrated GPU (all asics).
431  * Returns 0 on success, error on failure.
432  */
433 static int radeon_atpx_switchto(enum vga_switcheroo_client_id id)
434 {
435 	u16 gpu_id;
436 
437 	if (id == VGA_SWITCHEROO_IGD)
438 		gpu_id = ATPX_INTEGRATED_GPU;
439 	else
440 		gpu_id = ATPX_DISCRETE_GPU;
441 
442 	radeon_atpx_switch_start(&radeon_atpx_priv.atpx, gpu_id);
443 	radeon_atpx_switch_disp_mux(&radeon_atpx_priv.atpx, gpu_id);
444 	radeon_atpx_switch_i2c_mux(&radeon_atpx_priv.atpx, gpu_id);
445 	radeon_atpx_switch_end(&radeon_atpx_priv.atpx, gpu_id);
446 
447 	return 0;
448 }
449 
450 /**
451  * radeon_atpx_power_state - power down/up the requested GPU
452  *
453  * @id: GPU to power down/up
454  * @state: requested power state (0 = off, 1 = on)
455  *
456  * Execute the necessary ATPX function to power down/up the discrete GPU
457  * (all asics).
458  * Returns 0 on success, error on failure.
459  */
460 static int radeon_atpx_power_state(enum vga_switcheroo_client_id id,
461 				   enum vga_switcheroo_state state)
462 {
463 	/* on w500 ACPI can't change intel gpu state */
464 	if (id == VGA_SWITCHEROO_IGD)
465 		return 0;
466 
467 	radeon_atpx_set_discrete_state(&radeon_atpx_priv.atpx, state);
468 	return 0;
469 }
470 
471 /**
472  * radeon_atpx_pci_probe_handle - look up the ATPX handle
473  *
474  * @pdev: pci device
475  *
476  * Look up the ATPX handles (all asics).
477  * Returns true if the handles are found, false if not.
478  */
479 static bool radeon_atpx_pci_probe_handle(struct pci_dev *pdev)
480 {
481 	acpi_handle dhandle, atpx_handle;
482 	acpi_status status;
483 
484 	dhandle = ACPI_HANDLE(&pdev->dev);
485 	if (!dhandle)
486 		return false;
487 
488 	status = acpi_get_handle(dhandle, "ATPX", &atpx_handle);
489 	if (ACPI_FAILURE(status))
490 		return false;
491 
492 	radeon_atpx_priv.dhandle = dhandle;
493 	radeon_atpx_priv.atpx.handle = atpx_handle;
494 	return true;
495 }
496 
497 /**
498  * radeon_atpx_init - verify the ATPX interface
499  *
500  * Verify the ATPX interface (all asics).
501  * Returns 0 on success, error on failure.
502  */
503 static int radeon_atpx_init(void)
504 {
505 	int r;
506 
507 	/* set up the ATPX handle */
508 	r = radeon_atpx_verify_interface(&radeon_atpx_priv.atpx);
509 	if (r)
510 		return r;
511 
512 	/* validate the atpx setup */
513 	r = radeon_atpx_validate(&radeon_atpx_priv.atpx);
514 	if (r)
515 		return r;
516 
517 	return 0;
518 }
519 
520 /**
521  * radeon_atpx_get_client_id - get the client id
522  *
523  * @pdev: pci device
524  *
525  * look up whether we are the integrated or discrete GPU (all asics).
526  * Returns the client id.
527  */
528 static enum vga_switcheroo_client_id radeon_atpx_get_client_id(struct pci_dev *pdev)
529 {
530 	if (radeon_atpx_priv.dhandle == ACPI_HANDLE(&pdev->dev))
531 		return VGA_SWITCHEROO_IGD;
532 	else
533 		return VGA_SWITCHEROO_DIS;
534 }
535 
536 static const struct vga_switcheroo_handler radeon_atpx_handler = {
537 	.switchto = radeon_atpx_switchto,
538 	.power_state = radeon_atpx_power_state,
539 	.get_client_id = radeon_atpx_get_client_id,
540 };
541 
542 /**
543  * radeon_atpx_detect - detect whether we have PX
544  *
545  * Check if we have a PX system (all asics).
546  * Returns true if we have a PX system, false if not.
547  */
548 static bool radeon_atpx_detect(void)
549 {
550 	char acpi_method_name[255] = { 0 };
551 	struct acpi_buffer buffer = {sizeof(acpi_method_name), acpi_method_name};
552 	struct pci_dev *pdev = NULL;
553 	bool has_atpx = false;
554 	int vga_count = 0;
555 	bool d3_supported = false;
556 	struct pci_dev *parent_pdev;
557 
558 	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
559 		vga_count++;
560 
561 		has_atpx |= (radeon_atpx_pci_probe_handle(pdev) == true);
562 
563 		parent_pdev = pci_upstream_bridge(pdev);
564 		d3_supported |= parent_pdev && parent_pdev->bridge_d3;
565 	}
566 
567 	/* some newer PX laptops mark the dGPU as a non-VGA display device */
568 	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_OTHER << 8, pdev)) != NULL) {
569 		vga_count++;
570 
571 		has_atpx |= (radeon_atpx_pci_probe_handle(pdev) == true);
572 
573 		parent_pdev = pci_upstream_bridge(pdev);
574 		d3_supported |= parent_pdev && parent_pdev->bridge_d3;
575 	}
576 
577 	if (has_atpx && vga_count == 2) {
578 		acpi_get_name(radeon_atpx_priv.atpx.handle, ACPI_FULL_PATHNAME, &buffer);
579 		pr_info("vga_switcheroo: detected switching method %s handle\n",
580 			acpi_method_name);
581 		radeon_atpx_priv.atpx_detected = true;
582 		radeon_atpx_priv.bridge_pm_usable = d3_supported;
583 		radeon_atpx_init();
584 		return true;
585 	}
586 	return false;
587 }
588 
589 /**
590  * radeon_register_atpx_handler - register with vga_switcheroo
591  *
592  * Register the PX callbacks with vga_switcheroo (all asics).
593  */
594 void radeon_register_atpx_handler(void)
595 {
596 	bool r;
597 	enum vga_switcheroo_handler_flags_t handler_flags = 0;
598 
599 	/* detect if we have any ATPX + 2 VGA in the system */
600 	r = radeon_atpx_detect();
601 	if (!r)
602 		return;
603 
604 	vga_switcheroo_register_handler(&radeon_atpx_handler, handler_flags);
605 }
606 
607 /**
608  * radeon_unregister_atpx_handler - unregister with vga_switcheroo
609  *
610  * Unregister the PX callbacks with vga_switcheroo (all asics).
611  */
612 void radeon_unregister_atpx_handler(void)
613 {
614 	vga_switcheroo_unregister_handler();
615 }
616